1. Field of the Invention
This invention relates to a high security latch for a gate lock for a chain link fence.
2. Prior Art
Chain link fences are well known. Typically such fences are made of a support frame of pipe which supports a mesh of thick metal wire which forms a screen. The screen is secured to the frame by pieces of wire which surround the frame work and mesh at fixed intervals. To provide a gate in an opening formed by pipe and/or poles of a chain link fence, a pipe frame the size of the opening is hinged to a pipe on one side of the opening. Typically, an oar lock or fork latch is hingeably attached to the opposite side of the gate frame. When the gate is in the closed position, the oar lock or fork latch is moved to the horizontal position where it receives a pole of the fence in the U-shaped portion thereof.
Typically, to lock the gate openings are provided in the oar lock and the collar holding the oar lock to the gate. When the oar lock is in the closed position, i.e. horizontal, the openings in the lock and collar line up and a padlock is passed through the openings to lock them in their aligned position. With the lock in place, the oar lock cannot be moved from the horizontal closed position to the vertical open position. Thus the gate is locked.
The drawback of such a method of locking a chain link gate includes difficulty in opening and closing the lock and gate, the potential to lose or misplace the lock and the inherent weakness of an oar lock or fork latch to tampering by an intruder. Loss of the lock occurs frequently because the padlock has to be removed from the gate to complete the locking and unlocking operation. Further, in order to unlock the gate two hands must be used, one hand to hold and steady the lock and another hand for inserting the key to open the lock.
U.S. Pat. No. 4,691,541 to the inventor herein (McQuade), issued Sept. 8, 1987, eliminates the risk of losing or misplacing the lock because the locking device is always attached to the gate frame. At no time is the lock removed from the gate to complete its operation. Operational ease is attained because the lock is stationary and the key slot is accessible. To open the lock all that is necessary is to insert the key and turn. When the key is turned, the lock cylinder will pop out and release the lock bar from the oar lock. To lock the gate, the oar lock is merely moved to its horizontal, locking position and a push button cylinder is engaged to move its lock bar into an opening in the oar lock to fix the oar lock in position.
In McQuade the collar holding the lock and oar lock is modified from that typically used to retain an oar lock. The collar is in two pieces and sandwiches the pipe of the gate frame. Set screws/bolts pass through the collar causing the collar to engage the frame pipe. The lock system is comprised of several parts. Each of the parts is easily replaceable permitting quick and easy repair to the system. The lock provides a child proof gate lock with ease of installation. The lock is always in its proper locking position and cannot be misplaced.
A major problem remaining, not addressed by McQuade, inherent in the use of an oar lock or fork latch device for locking a gate, is that easy access can be obtained by an intruder. By simply prying the outside half of the fork outward, entry can be obtained. Double driveway gates are similarly easily opened by merely pushing hard enough on the gate. Such is often accomplished by a mere gust of wind.
Other gate latches of the prior art do not solve this foregoing problem. For example, by Youngworth, U.S. Pat. No. 2,666,660, and by Lening et al, U.S. Pat. No. 4,387,916. These gate latches all employ oar locks of generally standard configuration. Access to the oar lock is not protected and the oar lock itself is not locked to the gate pole to which it is connected.
The interlocking of the gate poles of chain link fences is found in the dual locking device of Joersz, U.S. Pat. No. 3,926,018. The Joersz invention, however, requires detachable dual clamps tightly clamping one pole to the other.
Other latch and lock devices are described in the following patents:
U.S. Pat. No. 4,592,578 to Martin; PA1 U.S. Pat. No. 3,934,436 to Candlin et al; PA1 U.S. Pat. No. 3,702,549 to Solovieff et al; PA1 U.S. Pat. No. 3,307,384 to Sinervo; PA1 U.S. Pat. No. 3,270,536 to Sprung; PA1 U.S. Pat. No. 3,083,561 to Sussing; PA1 U.S. Pat. No. 3,042,435 to Wiesler; PA1 U.S. Pat. No. 2,809,063 to Taylor; PA1 U.S. Pat. No. 2,074,759 to Richards; PA1 U.S. Pat. No. 2,194,408 to Sluss; PA1 U.S. Pat. No. 1,319,187 to Sumners; PA1 U.S. Pat. No. 1,179,852 to Louden; PA1 U.S. Pat. No. 303,225 to Jordan; and PA1 French Pat. No. 584,589 to Hutin.
None of these references teach or suggest the claimed gate locking device of this invention and the benefits derived therefrom.